Conventionally, in order to polish surfaces of metal, semiconductor substrates made from silicon, gallium arsenide and others, glasses, ceramics, etc., with utmost precision, polishing clothes have been used for a primary polishing process and a secondary polishing process which are executed before executing a final polishing process. Such a polishing cloth is produced by the steps of impregnating a nonwoven cloth with a solution of polyurethane resin and coagulating the resin-impregnated nonwoven cloth by immersing it in water which is substantially a nonsolvent. The nonwoven cloth is bonded and fixed with porous polyurethane resin having a multiplicity of fine through holes. According to this conventional polishing cloth, the porous structure of the polyurethane resin functions both to hold the polishing solution therein and to discharge the solution therefrom.
On the other hand, the porous polyurethane resin is apt to be deformed by pressure and heat generated while executing polishing. The use of the porous polyurethane resin often causes deterioration of the polishing performance because polishing particles clog themselves in the fine through holes. Also the surfaces of to-be-polished objects are caused to scratch. This, the conventional polishing cloth has problems regarding its quality and productivity. In addition, in recent years, a demand for high-pressure high-speed polishing has been increasing so rapidly that overall improvement of the polishing cloth is required urgently.